Dead Computer (again)

[Blade_Raver]

Good one

[Kogarashi]

*Sigh*

Ok, either I've had two identically defective motherboards in a row, or it's not the motherboard.

The replacement motherboard arrived in the mail today. Since I did a defective item RMA for replacement, it's the exact same model motherboard as the one I just sent back as possibly defective. I got it installed and everything hooked up again, and my computer booted up.

I did a little maintenance, installed the drivers from the motherboard CD, and made sure my internet connection was still working (since I'd gotten that installed with the previous copy of this mobo), and fired up Windows Update. I managed to get through all of the updates through SP3 and IE8 before Hubby and I sat down to watch a movie. Right before the movie started, I told the computer to reboot after installing the last batch of security updates and such.

Two hours later, I went over to check on it. The monitor was in power save mode, which wasn't surprising as it does that anyway after a while, especially if the computer has gone into standby. The computer wouldn't "wake up" though, so I hit the reset button on the case. I wasn't too worried yet, as it's done this once or twice before when trying to wake up from standby (though I don't know why).

The computer rebooted, I fired up Windows Update again to check to see if there were any more updates to be installed, and the computer decided to take me through setup of IE8's features. Right as I got to the end of it, just after hitting the Finish button, the monitor lost the signal and went into power save.

I haven't done anything else yet, since it's late here by this point and I don't want to break something. I plan on running that memtest I mentioned in a previous post first thing tomorrow, in the hopes that it'll be able to stay on long enough to finish the test and maybe give me some insight. Beyond that, I don't have much in the way of ideas. At this point, I think we can rule out the motherboard. I suspect something of overheating, since it varies how long it can stay on before the signal disappears (but seems to get progressively shorter in length the longer I work on it in a given day). Don't know what, though.

Help? Please?

[Geek King]

I have an idea. Take your PC and monitor to another room in the house (or at least an electrcal outlet that is not on the same circuit as the current outlet) and start it up. You may be getting micro-surges or slight brownouts through the power supply that is causing the monitor to flake out after a random period.

You may also want to try it at a friend's house just in case it is residence-wide. Right now, the only common thing through all these reports is the location of the computer, so let's rule that out.

[Dreamstalker]

I would also re-check something grounding to the case. The motherboard should be supported by brass standoffs (not sitting on the "bumps" inside the case), and the screw heads shouldn't be overhanging the small solder rings around the holes.

It could be possible that a screw was dropped, not noticed at the time and is now lurking behind the mobo (that happened to me once ), or that the PSU is just a bit too wimpy to support everything. Somewhere I have a site that will take your system specs and spit out the minimum required PSU wattage (ETA: site is here)

[Blade_Raver]

A question of curiosity - did you have the CPU/RAM replaced?

[Kogarashi]

Geek King: Haven't tried moving it to a different part of the apartment yet (or to another building), mostly because I was first running the memtest again at another friend's suggestion. After running for 2.5 hours with no issues, I went into the BIOS and left it sitting there on the hardware monitor just to keep an eye out to make sure the processor and motherboard weren't overheating. No temperature spikes, but half an hour later, the monitor lost the signal again.

Unfortunately, since then, the computer is giving me the original problem: no POST beep and only the lights and fans seem to get power.

Dreamstalker: nothing behind the motherboard except the standoffs it's supposed to be on. The screw heads aren't overhanging the rings, especially since I have those red paper (plastic?) washers to help separate the screw heads from the motherboard. I also made sure when installing this latest replacement board that nothing was touching where it shouldn't be.

The PSU calculators I've checked (including yours just now) indicate that the PSU is putting out more than enough power. Not sure if I entered everything into this latest one correctly, but others with the same info put in give me a ~300W requirement (the current PSU is 430W).

Blade_Raver: Not when I got the RMA for the motherboard, no.

At the moment, it looks like my options are to borrow a neighbor's multimeter to check the PSU's output that way, and to RMA all three purchased components in the hope that I get a working one (or to replace them with different models in case they don't want to play nice with each other for some reason). I've got until Saturday (I think) to do returns on them.